The Session Initiation Protocol (SIP) protocol is an end-to-end client-server signaling protocol for initiating, modifying, and terminating interactive user sessions supporting voice, instant messaging, video, online gaming, and the like. The SIP protocol, which is utilized in next-generation networks such as Internet Protocol (IP) Multimedia Subsystem (IMS) networks, enables communication between distributed elements (e.g., between SIP user agents (UAs)). Using the SIP protocol, SIP messages exchanged between SIP UAs traverse a series of SIP network elements (known as proxies). Unfortunately, due to incorrectly configured network elements or malicious network attacks, a forwarding loop may form such that a SIP message is repeatedly forwarded between SIP network elements, thereby preventing delivery of the SIP message to the intended SIP UA and causing a high message processing load. Since forwarding loops may occur in networks utilizing SIP (as well as networks utilizing other telecommunication protocols), several measures have been implemented to attempt to reduce forwarding loops.
In one potential solution, for example, a client device may add a “max-forwards” header field to the header of a SIP message in order to limit the number of times the SIP message is forwarded before a forwarding loop is detected (i.e., a SIP message may only be forwarded N times (e.g., N=70) before a forwarding loop is detected). Disadvantageously, use of a “max-forwards” header field may cause numerous problems. If the “max-forwards” header field value (N) is set too low, valid service provisioning may be overly restricted. If the “max-forwards” header field value (N) is set too high, significant network resources may be consumed. Furthermore, a forwarding loop error message generated in response to detection of a forwarding loop may be forwarded along the traversed path, thereby resulting in additional consumption of network resources.